Maths:Topic Four: "Measures of dispersion : Part 1"

Topic Four: "Measures of dispersion : Part 1"

The first part of "Measures Of Dispersion" is: "Average".

"Average"

Average consist of 3:

1. Mean
2. Median
3. Mode

1. Mean

Mean is where you need to find the average. For example:

1,2,3,4,5,6,7,8

The the steps for finding Mean is:

• To find the total or sum of the number:
• SUM= 1+2+3+4+5+6+7+8 
• SUM= 36 

• Then, you just need to divide the SUM by the values of the number:

• 1,2,3,4,5,6,7,8 = the total number of this values are : 8
•  So, 36/8 = 4.5 

• The Mean is equal to : "4.5"

Here is another example:

10,2,8,7,11,9,5

• First Step: Find the SUM; 
• SUM= 10+2+8+7+11+9+5
• SUM= 52

• Second Step: Divide by total number of of the values
• 10,2,8,7,11,9,5 = the total number of values: 7
• So, 52 / 7 = 7.43

• The Mean is equal to : "7.43"

Here is another example: but this time with specific request:

• Find the MEAN of the following numbers below. Give your answer in 2 DECIMAL PLACES.  

28,1,9,56,100.3,2,1,2 

• SUM = 28+1+9+56+100+3+2+1+2
• SUM = 202

• Total number of values: 9
• MEAN = 202 / 9
• MEAN = 22.44444444......(Original)
• MEAN = 22.44 (2 Decimal Places)

KEY-POINTS: 

 First you need to find the SUM of the values. Then, you DIVIDE the SUM by the NUMBER OF VALUES.  

TO BE CONTINUE...